It's important to note that not one of those probrewers on that thread is batch sparging OR BIAB brewing. They get by with short mashes because they do 90minfly sparges (usually) and conversion continues for a good period of time after that begins.
It's not exactly apples to apples. There is also more then just conversion going on in the mash tun, there is a breakdown of longer chain sugars into shorter chain sugars. You can get complete conversion without breaking down the longer chains and you'll get a nice full bodied beer out of it with a higher FG. If you give the enzymes more time to work, you can get those dry and (digestible as the Euro brewers refer to it) beers that many styles require, and many brewers/beer drinkers, enjoy.
There's a balance to be struck. Some dude on pro brewer says "conversion takes place in as little as 8 minutes" and it's off to the races, but make sure you're getting what you want out of your mash. That's the whole purpose of being an AG homebrewer isn't it? To exercise a level of control over your final product that extract might not give you? If you're going to do an 8 minute mash because first and foremost you want to cut time, I sincerely think you'd be better off using extract. If you can't low and slow a mash to get a very dry finish (ala Pliny the Younger and other popular "triple IPAs") then what you're going to get from high quality extract is well worth the time savings.
I know Owly said his whole point was to see how fast he could do an AG BIAB brewday, but I'm submitting some food for thought here. At what point are you missing a huge opportunity to cut time by insisting on a mash process that yields you the same product extract gives you?
The 10 minute mash did NOT give full attenuation....... nor did I expect it to. The 20 minute mash with a fine crush DID give full attenuation. I haven't bettered it by mashing as long as two hours.
Controlling the exact amount of fermentables is something that requires some pretty precise techniques. The crush must be exactly the same, the strike temp and mash time must be exactly the same, etc. It's something we may be able to come close to, but I suspect repeatability is not as good as we would like it to be. How many of us manage PH and mineral content as well as we could..... or bother at all?
The goal is NOT to achieve ultimate attenuation with virtually no residual sugars, it's to hit a target. Repeatability is where it's at for many people who brew according to a specific recipe. Go to McDonalds, and you get the same product every time........ It may be garbage, but a rat burger is always the same! Open a can of Bud, Oly, Coors, etc, and it will always be the same. Most of us strive for repeatability by replicating our process as exactly as possible each time.
Let me suggest that perhaps the long slow mash is sometimes NOT going to give you what you want........ too dry, and the 10 minute mash is not going to give you what you want... too sweet, but that in some cases doing a 10 minute conversion and immediately drawing off a percentage of the wort and taking it to mash out temps rapidly, while allowing the remainder to work in the Beta range for an extended period, then combining the two for the boil, might be a way to achieve a very specific product again and again.
But we have wonderful tools in the form of a large array of crystal malts. We have tools that the old time commercial brewers didn't.... And tools that the home brewer of yesteryear didn't........... I was one of those who brewed when it was illegal to brew beer at home (but you could brew wine) (60's). You could buy almost nothing...... light LME, and dark LME...... hop flavored or not hop flavored. You might find some garden hops, but you couldn't buy hops in the store. We talked about malting our own grains, and browsed the library for information...... it was scarce. We live in the Halcyon days of home brewing. Not only do we have an incredible array of ingredients available.....
(I have 18 varieties of hops in the freezer right now, 50 pounds of two row, various quantities of different crystal malts, victory malt, Melanoidin malt, Carapils, chocolate malt, roast barley, wheat malt, rye malt, corn sugar, flaked corn, torrified wheat, and a pound of amylase).
The suggestion that somehow mashing rapidly gives you the same product that extract brewing does is beyond absurd. Time, in and of itself is NOT what makes a good beer......... aging perhaps, but writing this whole effort off as reducing brewing to something equivalent to extract brewing is simple minded, and wrong. It fails to take many factors into account.
H.W.
